FIG 2.

Identification of the cryo-EM density corresponding to the holdfast anchor complex. (A) A virtual slice through a tomogram of a Caulobacter crescentus CB15 cell. The holdfast is visible near the stalk tip (red arrowhead), where it appears anchored to a density directly underneath the outer membrane (marked). The holdfast displays visible granularity (blue arrowheads). (B and C) Zoomed view of the CB15 stalk tips showing the presence of the holdfast anchor complex together with the holdfast.